This invention pertains generally to input devices for information processing systems and, more particularly, to a keyboard and method which are particularly useful for inputting Chinese ideographs and other characters selected from sets of virtually unlimited size.
As used herein, the term xe2x80x9ccharacterxe2x80x9d is used in its broadest sense and encompasses all forms of graphic representations including but not limited to letters, numbers, symbols, ideograms, icons, pictures and other images.
In the Chinese language, there are approximately 40,000 ideographs or characters, of which about 2500-3000 are in common use. A keyboard or typewriter for the Chinese language must, therefore, be capable of inputting or printing on the order of at least 2500-3000 characters.
One type of Chinese typewriter heretofore provided has separate printing elements for the most commonly used characters arranged in a matrix, with a stylus by which the element for a desired character is picked up and moved into position for printing. When uncommon characters are required, they must be individually selected from a separate tray and moved into position for use. This is a time consuming process, and a skilled operator can only print about ten characters with such a machine.
Another technique which has been employed in Chinese typewriters is to store data for the various characters in the memory of a computer and to address this information to control the operation of a printer. This technique requires a substantial amount of memory to store the data for a large set, and the characters which can be printed are limited to those for which data has been stored.
A number of different techniques have also been employed for inputting Chinese characters to computers and other data processing devices. Two of the more widely used of these techniques utilize keyboards for inputting information about the desired character in the form phonics or radicals, with software for analyzing that information which and presenting images of possible characters on the monitor screen from which the user can select the desired character. With phonics, the information input through the keyboard describes the desired character in terms of its sound, and with radicals, the information corresponds to the visual appearance of different parts of the character. Both of these techniques are relatively slow and cumbersome and, therefore, not well suited for applications such as word processing where characters need to be input at a relatively rapid rate.
U.S. Pat. 4,722,621 describes a keyboard assembly and typewriter in which a relatively large number of characters are arranged in an array on a keyboard panel, with a character selector which is moved manually about the array of characters and linked to a group of daisy wheel printing elements to effect printing of a desired character. This patent also describes the use of a magnetic medium which is transduced in accordance with the position of the character selector to provide an audible pronunciation of the selected character or to provide address signals for a read only memory in which character data is stored.
It is in general an object of the invention to provide a new and improved ideographic keyboard and method.
Another object of the invention is to provide an ideographic keyboard and method of the above character which are particularly suitable for inputting Chinese ideographs and other characters selected from sets of relatively large size.
Another object of the invention is to provide an ideographic keyboard and method of the above character which can input relatively complex characters, such as Chinese ideograms, at a faster rate than systems heretofore provided.
Another object of the invention is to provide an ideographic keyboard and method of the above character which can be implemented relatively inexpensively.
These and other objects are achieved in accordance with the invention by providing an ideographic keyboard and method in which an array of characters are printed on one side of a panel and optically readable data corresponding to the characters is recorded on the other side of the panel. A character selector is moved about the first side the panel for selective alignment with the characters, and an optical reader is linked to the character selector for movement about the recorded data in concert with the character selector. The data corresponding to a selected character is read, and a coded signal for the selected character is output in response to the data which is read. In one disclosed embodiment, the data is recorded in the form of bar coding, and the reader comprises a bar code reader. Precise alignment of the reader with the data for the selected character is assured by reading data from a region larger than the data field itself and extracting the character data in software.